Long-term optical data storage (ODS) technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data. Here, ODS with an ultralong lifetime of 2×10⁷ years is attained with single ultrafast laser pulse induced reduction of Eu³⁺ ions and tailoring of optical properties inside the Eu-doped aluminosilicate glasses. We demonstrate that the induced local modifications in the glass can stand against the temperature of up to 970 K and strong ultraviolet light irradiation with the power density of 100 kW/cm². Furthermore, the active ions of Eu²⁺ exhibit strong and broadband emission with the full width at half maximum reaching 190 nm, and the photoluminescence (PL) is flexibly tunable in the whole visible region by regulating the alkaline earth metal ions in the glasses. The developed technology and materials will be of great significance in photonic applications such as long-term ODS.Long-term optical data storage (ODS) technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data. Here, ODS with an ultralong lifetime of 2×10⁷ years is attained with single ultrafast laser pulse induced reduction of Eu³⁺ ions and tailoring of optical properties inside the Eu-doped aluminosilicate glasses. We demonstrate that the induced local modifications in the glass can stand against the temperature of up to 970 K and strong ultraviolet light irradiation with the power density of 100 kW/cm². Furthermore, the active ions of Eu²⁺ exhibit strong and broadband emission with the full width at half maximum reaching 190 nm, and the photoluminescence (PL) is flexibly tunable in the whole visible region by regulating the alkaline earth metal ions in the glasses. The developed technology and materials will be of great significance in photonic applications such as long-term ODS.

The past two decades have seen a drastic progress in the development of semiconducting metal-halide perovskites (MHPs) from both the fundamentally scientific and technological points of view. The excellent optoelectronic properties and device performance make perovskites very attractive to the researchers in materials, physics, chemistry and so on. To fully explore the potential of perovskites in the applications, various techniques have been demonstrated to synthesize perovskites, modify their structures, and create patterns and devices. Among them, photo-processing has been revealed to be a facile and general technique to achieve these aims. In this review, we discuss the mechanisms of photo-processing of perovskites and summarize the recent progress in the photo-processing of perovskites for synthesis, patterning, ion exchange, phase transition, assembly, and ion migration and redistribution. The applications of photo-processed perovskites in photovoltaic devices, lasers, photodetectors, light-emitting diodes (LEDs), and optical data storage and encryption are also discussed. Finally, we provide an outlook on photo-processing of perovskites and propose the promising directions for future researches. This review is of significance to the researches and applications of perovskites and also to uncover new views on the light-matter interactions.The past two decades have seen a drastic progress in the development of semiconducting metal-halide perovskites (MHPs) from both the fundamentally scientific and technological points of view. The excellent optoelectronic properties and device performance make perovskites very attractive to the researchers in materials, physics, chemistry and so on. To fully explore the potential of perovskites in the applications, various techniques have been demonstrated to synthesize perovskites, modify their structures, and create patterns and devices. Among them, photo-processing has been revealed to be a facile and general technique to achieve these aims. In this review, we discuss the mechanisms of photo-processing of perovskites and summarize the recent progress in the photo-processing of perovskites for synthesis, patterning, ion exchange, phase transition, assembly, and ion migration and redistribution. The applications of photo-processed perovskites in photovoltaic devices, lasers, photodetectors, light-emitting diodes (LEDs), and optical data storage and encryption are also discussed. Finally, we provide an outlook on photo-processing of perovskites and propose the promising directions for future researches. This review is of significance to the researches and applications of perovskites and also to uncover new views on the light-matter interactions.

We report on a conceptually new type of waveguide in glass by femtosecond laser direct writing, namely, photonic lattice-like waveguide (PLLW). The PLLW’s core consists of well-distributed and densified tracks with a sub-micron size of 0.62 µm in width. Specifically, a PLLW inscribed as hexagonal-shape input with a ring-shape output side was implemented to converse Gaussian mode to doughnut-like mode, and high conversion efficiency was obtained with a low insertion loss of 1.65 dB at 976 nm. This work provides a new freedom for design and fabrication of the refractive index profile of waveguides with sub-micron resolution and broadens the functionalities and application scenarios of femtosecond laser direct-writing waveguides in future 3D integrated photonic systems.

Printing stable color with a lithography-free and environment-friendly technique is in high demand for applications. We report a facile strategy of ultrafast laser direct writing (ULDW) to produce large-scale embedded structural colors inside transparent solids. The diffraction effect of gratings enables effective generation of structural colors across the entire visible spectrum. The structural colors inside the fused silica glass have been demonstrated to exhibit excellent thermal stability under high temperature up to 1200°C, which promises that the written information can be stable for long time even with unlimited lifetime at room temperature. The structural colors in the applications of coloring, anti-counterfeiting, and information storage are also demonstrated. Our studies indicate that the presented ULDW allows for fabricating large-scale and high thermal-stability structural colors with prospects of three-dimensional patterning, which will find various applications, especially under harsh conditions such as high temperature.

Integrated photonics is attracting considerable attention and has found many applications in both classical and quantum optics, fulfilling the requirements for the ever-growing complexity in modern optical experiments and big data communication. Femtosecond (fs) laser direct writing (FLDW) is an acknowledged technique for producing waveguides (WGs) in transparent glass that have been used to construct complex integrated photonic devices. FLDW possesses unique features, such as three-dimensional fabrication geometry, rapid prototyping, and single step fabrication, which are important for integrated communication devices and quantum photonic and astrophotonic technologies. To fully take advantage of FLDW, considerable efforts have been made to produce WGs over a large depth with low propagation loss, coupling loss, bend loss, and highly symmetrical mode field. We summarize the improved techniques as well as the mechanisms for writing high-performance WGs with controllable morphology of cross-section, highly symmetrical mode field, low loss, and high processing uniformity and efficiency, and discuss the recent progress of WGs in photonic integrated devices for communication, topological physics, quantum information processing, and astrophotonics. Prospective challenges and future research directions in this field are also pointed out.